› IT any of the set of moving parts that you press with your fingers on a computer, etc. to produce letters, numbers, or symbols: Press any key to continue.
› GRAPHS & CHARTS a list of the symbols used in a map, chart, or book with explanations of what they mean: For an explanation of these symbols, see key below.
the key (to sth) › the best or only way to achieve something: The key is to prioritize your work, and to keep to your schedule. Hard work is the key to success. A focus on training is often the key to unlocking potential. → See also Alt key, arrow key, control key, escape, hot key, scroll key, shift key